firstly, i check the x_rotation and y_rotation by using
/data get entity @s
i see that the range of X is from -360 to 360 and the range if Y is from -90 to 90
and then, i use
/execute as @s[x_rotation=-45..45] run say SOUTH & /execute as @s[y_rotation=-45..45] run say STRAIGHT(as i am turning at the right rotation)and it worked !!!
but later, i use
/execute as @s[x_rotation=-135..-45] run say EAST & /execute as @s[y_rotation=-90..-45] run say UP & other commands to check the rotation(even i am turning at the right rotation)but it didn't worked !!!
i don't know whether i'm using the fault command or the minecraft cannot check the number from -180 to -45 and from 180 to 45 ???
it's also appeared in 1.16.4 and 1.16.5-rc1